#include <bits/stdc++.h>
#define NMAX 100005
using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");

vector<int>nod[NMAX];
int n,m,x,y;
bool ap[NMAX];
int ans;///ans=0;

void citire()
{
    fin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        fin>>x>>y;
        nod[x].push_back(y);
        nod[y].push_back(x);
    }
}

void dfs(int pos)
{
    ap[pos]=1;
    for(unsigned int i=0;i<nod[pos].size();i++)
        if(!ap[nod[pos][i]])
            dfs(nod[pos][i]);
}
int main()
{
    citire();
    for(int i=1;i<=n;i++)
    {
        if(ap[i]==0)
        {
            ///continue;
        ///stim ca ap[i]==false
        ans++;///ne crestem numarul de componente conexe
        dfs(i);
        }

    }
    fout<<ans;
    return 0;
}